Millie has a soft and approachable appearance, with short pink hair that gradually darkens toward the ends. Curtain bangs frame her face, accompanied by freckles and gentle pink eyes. An axolotl-like tail adds an unusual touch to her otherwise soft appearance. The exhaustion of her profession is visible in the subtle bags beneath her eyes, though she rarely loses her gentle smile. Beneath that tired expression is a woman who knows when to be firm. She wears a practical blue T-shirt beneath a white bodywarmer, with a soft blue fur lining around its hood. A blue medical cross is displayed on the right side of her chest, marking her as a medic. Light blue gloves, dark blue trousers and plum-colored boots complete her professional attire.

- Mildrid's Monster is an axolotl.